Mathematical modeling of limestone dissolution in batch stirred tank reactors in presence of a diluted strong acid.

The rate of limestone dissolution determines the need for limestone excess in flue gas desulfurization processes and therefore affects the cost of makeup and waste disposal. For this reason a better understanding of the limestone performance toward desulfurization can have reasonable economical effects. Utilizing a good mathematical model it is possible to optimize the parameters involved in flue gas desulfurization. In the present work a mathematical model describing the transport phenomena occurring in limestone-strong acid reaction in small BSTRs (Batch Stirred Tank Reactors) was developed and evaluated. The particle size distribution and the chemical reactivity were considered as primary factors determining the volume variation of the natural limestone. The model together with the experimental procedure provides a new tool for measuring the properties of chemicals used in flue gas desulfurization FGD.